2D fuselage structures and sit on top, no sit In!

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by erkki67, Nov 1, 2019.

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  1. Nov 16, 2019 #61

    BJC

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    The CGS Hawk uses a curved tail boom. Not sure of the alloy.

    Anyone know how they bent it?


    BJC
     
  2. Nov 16, 2019 #62

    rtfm

    rtfm

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    Hi,
    I get that this might be a first sketch, but there are a number of things you should probably re-think. First, if the man is drawn to scale, he's not even going to be able to get a single butt-cheek onto that miniature chair. Which is way too far forward anyway.

    The wing chord looks way too small, and why have all that structure behind the seat? Why not extend your structure rearwards and do away with the turtleback stuff altogether?

    HBA_design.png
     
  3. Nov 17, 2019 #63

    DaveK

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    “Why not extend your structure rearwards and do away with the turtleback stuff altogether?”

    Exactly what I was thinking. Bring a member down from the wing connection to the tail. It would massively reduce the demands on your structure. Only reason to use the low mounted skinny boom is for pusher prop clearance. Tractor prop, so no good reason to do as shown.
     
  4. Nov 17, 2019 #64

    wanttobuild

    wanttobuild

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    Rotax618
    Thanks for that, learned something about 2024 that I did not know.
    I have a book on pipe benders and how the amateur can make them.
    So, maybe I better stick to steel for bending.
    I hope others see your post because there is a lot of bent aluminum tube out there.
     
  5. Nov 19, 2019 #65

    erkki67

    erkki67

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    03F1227E-DD57-47CC-83A2-85C3EE7BC4B8.jpeg 692386B3-A6EA-4FE1-930C-1E904800AF69.jpeg 16C2D4D3-2B51-4B19-B305-1238ECC92865.jpeg

    One is the enhanced Affordaplane, the other the Monotube, why not combining both into one design?
     
  6. Nov 19, 2019 #66

    rotax618

    rotax618

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    9DCE11BF-2603-4C8A-B523-93218CABB2BD.jpeg For a pusher you can’t get much simpler than this arrangement.
     
  7. Nov 20, 2019 #67

    erkki67

    erkki67

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    What kind of bird is this?
     
  8. Nov 20, 2019 #68

    erkki67

    erkki67

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    07CFCB54-7D09-40B8-8A44-FBB847CD195C.jpeg
    what about combining aluminum tubing for the the lower and upper longeron and having a bent steel tube for the engine mount and lower cockpit longeron.
    All the fuzzy parts could be welded directly to the beam.
     
  9. Nov 20, 2019 #69

    rotax618

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    5EBB13A4-6CA8-4A02-B2CF-77764B9F2535.jpeg It is the basic frame of one of these, the enclosed pod is optional.
     
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  10. Nov 20, 2019 #70

    rotax618

    rotax618

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    FFFCEDB9-AA55-4D28-AD5A-A75BF36484ED.jpeg What the frame looks like
     
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  11. Nov 20, 2019 #71

    erkki67

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    It looks like a moyes inspired craft.
     
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  12. Nov 20, 2019 #72

    Hephaestus

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    Pretty sure thats rotax618's own boorabee design :)
     
  13. Nov 20, 2019 #73

    rotax618

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    1BB9CE60-6C6E-470C-8B10-9E657F107CD6.jpeg Yes here are some of them at a fly-in in 2001.
     
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  14. Nov 21, 2019 #74

    cluttonfred

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  15. Nov 21, 2019 #75

    rotax618

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    The Boorabee is a very simple aircraft, I built several aircraft including a couple of Drifter like aircraft before I designed the Boorabee. The Drifters were great but after a days flying I would be sunburnt and windburnt, and enclosing a Drifter is not so simple.
    I used the Drifter tube but shorter (made it easier to crush the front for footpegs and the rear for tailpost, did away with the unnecessary fuselarge pans.
    I completely re-designed the wing to use fibreglass (later carbon and kevlar) ribs, a main spar consisting of 2 off 40mmx.6mmdrawn tube top and bottom chords with 1.6mm shear plates on either side between alternate ribs and a 44mm drawn tube trailing edge spar.
    The wings incorporated 50litre fuel tanks moulded into eachwing root.
    I could post a few more sketches if anyone is interested.
    A friend of mine used the plug O made for the pod mould and built a similar aircraft called a Shuttle, he used a 100mmx75mmxapprox 2.5mm rectangular boom tube, he mig welded the foot pegs and rudder post. The Shuttles flew well but the aileron control system wasn't rigid enough and there were instances of aileron flutter, also he usea a single strut making the wing less torsionally strong.
    The pod is non structural.
     
  16. Nov 21, 2019 #76

    erkki67

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    Go ahead!
     
  17. Nov 21, 2019 #77

    rotax618

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    19A85FA1-F3D9-46DD-9FE3-64AC13BF9B26.jpeg BE310E00-CC5B-4445-8112-E854838BFD8B.jpeg 33D94267-AE2B-40E0-98C1-A7B3D9914F7F.png 3F528C14-981E-4701-B126-FD23BB7AC442.jpeg BE357110-7BDC-4EF0-B03D-5DCDD0834CB6.jpeg 2FB09607-C72A-4A8A-A262-BCAC4E43EFF3.jpeg 47B8705E-B0AA-4670-9C98-B5A071BAB430.jpeg F0384AC1-79FC-4684-A387-55606BB11941.jpeg 2C12A8DF-5B2B-488C-8FCA-C4D6B147FEB7.jpeg 4EA0E075-B8BF-49FA-BF3D-8CCB861DC7B8.jpeg The plans were drawn over 20 years ago using Visual Cadd.
     
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  18. Nov 21, 2019 #78

    rotax618

    rotax618

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    I don’t know how to upload PDFs and you can only upload 10 files at a time.
     
  19. Nov 21, 2019 #79

    cluttonfred

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    Very cool, thanks for sharing the drawings! As far as I know, it's just the "Upload a File" button but there is probably a file size limit.
     
  20. Nov 21, 2019 #80

    FritzW

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    Just like uploading a photo, drag the PDF to the post and drop it.

    Nice airplane! Have you made a CAD model of it yet?
     

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